1 files changed, 350 insertions, 0 deletions
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_pll.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_pll.c
new file mode 100644
index 000000000000..d15314957732
--- /dev/null
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_pll.c
@@ -0,0 +1,350 @@
+/*
+ * Copyright 2014 Advanced Micro Devices, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+#include <drm/drmP.h>
+#include <drm/amdgpu_drm.h>
+#include "amdgpu.h"
+#include "atom.h"
+#include "atombios_encoders.h"
+#include <asm/div64.h>
+#include <linux/gcd.h>
+
+/**
+ * amdgpu_pll_reduce_ratio - fractional number reduction
+ *
+ * @nom: nominator
+ * @den: denominator
+ * @nom_min: minimum value for nominator
+ * @den_min: minimum value for denominator
+ *
+ * Find the greatest common divisor and apply it on both nominator and
+ * denominator, but make nominator and denominator are at least as large
+ * as their minimum values.
+ */
+static void amdgpu_pll_reduce_ratio(unsigned *nom, unsigned *den,
+				    unsigned nom_min, unsigned den_min)
+{
+	unsigned tmp;
+
+	/* reduce the numbers to a simpler ratio */
+	tmp = gcd(*nom, *den);
+	*nom /= tmp;
+	*den /= tmp;
+
+	/* make sure nominator is large enough */
+	if (*nom < nom_min) {
+		tmp = DIV_ROUND_UP(nom_min, *nom);
+		*nom *= tmp;
+		*den *= tmp;
+	}
+
+	/* make sure the denominator is large enough */
+	if (*den < den_min) {
+		tmp = DIV_ROUND_UP(den_min, *den);
+		*nom *= tmp;
+		*den *= tmp;
+	}
+}
+
+/**
+ * amdgpu_pll_get_fb_ref_div - feedback and ref divider calculation
+ *
+ * @nom: nominator
+ * @den: denominator
+ * @post_div: post divider
+ * @fb_div_max: feedback divider maximum
+ * @ref_div_max: reference divider maximum
+ * @fb_div: resulting feedback divider
+ * @ref_div: resulting reference divider
+ *
+ * Calculate feedback and reference divider for a given post divider. Makes
+ * sure we stay within the limits.
+ */
+static void amdgpu_pll_get_fb_ref_div(unsigned nom, unsigned den, unsigned post_div,
+				      unsigned fb_div_max, unsigned ref_div_max,
+				      unsigned *fb_div, unsigned *ref_div)
+{
+	/* limit reference * post divider to a maximum */
+	ref_div_max = min(128 / post_div, ref_div_max);
+
+	/* get matching reference and feedback divider */
+	*ref_div = min(max(DIV_ROUND_CLOSEST(den, post_div), 1u), ref_div_max);
+	*fb_div = DIV_ROUND_CLOSEST(nom * *ref_div * post_div, den);
+
+	/* limit fb divider to its maximum */
+	if (*fb_div > fb_div_max) {
+		*ref_div = DIV_ROUND_CLOSEST(*ref_div * fb_div_max, *fb_div);
+		*fb_div = fb_div_max;
+	}
+}
+
+/**
+ * amdgpu_pll_compute - compute PLL paramaters
+ *
+ * @pll: information about the PLL
+ * @dot_clock_p: resulting pixel clock
+ * fb_div_p: resulting feedback divider
+ * frac_fb_div_p: fractional part of the feedback divider
+ * ref_div_p: resulting reference divider
+ * post_div_p: resulting reference divider
+ *
+ * Try to calculate the PLL parameters to generate the given frequency:
+ * dot_clock = (ref_freq * feedback_div) / (ref_div * post_div)
+ */
+void amdgpu_pll_compute(struct amdgpu_pll *pll,
+			u32 freq,
+			u32 *dot_clock_p,
+			u32 *fb_div_p,
+			u32 *frac_fb_div_p,
+			u32 *ref_div_p,
+			u32 *post_div_p)
+{
+	unsigned target_clock = pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV ?
+		freq : freq / 10;
+
+	unsigned fb_div_min, fb_div_max, fb_div;
+	unsigned post_div_min, post_div_max, post_div;
+	unsigned ref_div_min, ref_div_max, ref_div;
+	unsigned post_div_best, diff_best;
+	unsigned nom, den;
+
+	/* determine allowed feedback divider range */
+	fb_div_min = pll->min_feedback_div;
+	fb_div_max = pll->max_feedback_div;
+
+	if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV) {
+		fb_div_min *= 10;
+		fb_div_max *= 10;
+	}
+
+	/* determine allowed ref divider range */
+	if (pll->flags & AMDGPU_PLL_USE_REF_DIV)
+		ref_div_min = pll->reference_div;
+	else
+		ref_div_min = pll->min_ref_div;
+
+	if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV &&
+	    pll->flags & AMDGPU_PLL_USE_REF_DIV)
+		ref_div_max = pll->reference_div;
+	else
+		ref_div_max = pll->max_ref_div;
+
+	/* determine allowed post divider range */
+	if (pll->flags & AMDGPU_PLL_USE_POST_DIV) {
+		post_div_min = pll->post_div;
+		post_div_max = pll->post_div;
+	} else {
+		unsigned vco_min, vco_max;
+
+		if (pll->flags & AMDGPU_PLL_IS_LCD) {
+			vco_min = pll->lcd_pll_out_min;
+			vco_max = pll->lcd_pll_out_max;
+		} else {
+			vco_min = pll->pll_out_min;
+			vco_max = pll->pll_out_max;
+		}
+
+		if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV) {
+			vco_min *= 10;
+			vco_max *= 10;
+		}
+
+		post_div_min = vco_min / target_clock;
+		if ((target_clock * post_div_min) < vco_min)
+			++post_div_min;
+		if (post_div_min < pll->min_post_div)
+			post_div_min = pll->min_post_div;
+
+		post_div_max = vco_max / target_clock;
+		if ((target_clock * post_div_max) > vco_max)
+			--post_div_max;
+		if (post_div_max > pll->max_post_div)
+			post_div_max = pll->max_post_div;
+	}
+
+	/* represent the searched ratio as fractional number */
+	nom = target_clock;
+	den = pll->reference_freq;
+
+	/* reduce the numbers to a simpler ratio */
+	amdgpu_pll_reduce_ratio(&nom, &den, fb_div_min, post_div_min);
+
+	/* now search for a post divider */
+	if (pll->flags & AMDGPU_PLL_PREFER_MINM_OVER_MAXP)
+		post_div_best = post_div_min;
+	else
+		post_div_best = post_div_max;
+	diff_best = ~0;
+
+	for (post_div = post_div_min; post_div <= post_div_max; ++post_div) {
+		unsigned diff;
+		amdgpu_pll_get_fb_ref_div(nom, den, post_div, fb_div_max,
+					  ref_div_max, &fb_div, &ref_div);
+		diff = abs(target_clock - (pll->reference_freq * fb_div) /
+			(ref_div * post_div));
+
+		if (diff < diff_best || (diff == diff_best &&
+		    !(pll->flags & AMDGPU_PLL_PREFER_MINM_OVER_MAXP))) {
+
+			post_div_best = post_div;
+			diff_best = diff;
+		}
+	}
+	post_div = post_div_best;
+
+	/* get the feedback and reference divider for the optimal value */
+	amdgpu_pll_get_fb_ref_div(nom, den, post_div, fb_div_max, ref_div_max,
+				  &fb_div, &ref_div);
+
+	/* reduce the numbers to a simpler ratio once more */
+	/* this also makes sure that the reference divider is large enough */
+	amdgpu_pll_reduce_ratio(&fb_div, &ref_div, fb_div_min, ref_div_min);
+
+	/* avoid high jitter with small fractional dividers */
+	if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV && (fb_div % 10)) {
+		fb_div_min = max(fb_div_min, (9 - (fb_div % 10)) * 20 + 60);
+		if (fb_div < fb_div_min) {
+			unsigned tmp = DIV_ROUND_UP(fb_div_min, fb_div);
+			fb_div *= tmp;
+			ref_div *= tmp;
+		}
+	}
+
+	/* and finally save the result */
+	if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV) {
+		*fb_div_p = fb_div / 10;
+		*frac_fb_div_p = fb_div % 10;
+	} else {
+		*fb_div_p = fb_div;
+		*frac_fb_div_p = 0;
+	}
+
+	*dot_clock_p = ((pll->reference_freq * *fb_div_p * 10) +
+			(pll->reference_freq * *frac_fb_div_p)) /
+		       (ref_div * post_div * 10);
+	*ref_div_p = ref_div;
+	*post_div_p = post_div;
+
+	DRM_DEBUG_KMS("%d - %d, pll dividers - fb: %d.%d ref: %d, post %d\n",
+		      freq, *dot_clock_p * 10, *fb_div_p, *frac_fb_div_p,
+		      ref_div, post_div);
+}
+
+/**
+ * amdgpu_pll_get_use_mask - look up a mask of which pplls are in use
+ *
+ * @crtc: drm crtc
+ *
+ * Returns the mask of which PPLLs (Pixel PLLs) are in use.
+ */
+u32 amdgpu_pll_get_use_mask(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_crtc *test_crtc;
+	struct amdgpu_crtc *test_amdgpu_crtc;
+	u32 pll_in_use = 0;
+
+	list_for_each_entry(test_crtc, &dev->mode_config.crtc_list, head) {
+		if (crtc == test_crtc)
+			continue;
+
+		test_amdgpu_crtc = to_amdgpu_crtc(test_crtc);
+		if (test_amdgpu_crtc->pll_id != ATOM_PPLL_INVALID)
+			pll_in_use |= (1 << test_amdgpu_crtc->pll_id);
+	}
+	return pll_in_use;
+}
+
+/**
+ * amdgpu_pll_get_shared_dp_ppll - return the PPLL used by another crtc for DP
+ *
+ * @crtc: drm crtc
+ *
+ * Returns the PPLL (Pixel PLL) used by another crtc/encoder which is
+ * also in DP mode.  For DP, a single PPLL can be used for all DP
+ * crtcs/encoders.
+ */
+int amdgpu_pll_get_shared_dp_ppll(struct drm_crtc *crtc)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_crtc *test_crtc;
+	struct amdgpu_crtc *test_amdgpu_crtc;
+
+	list_for_each_entry(test_crtc, &dev->mode_config.crtc_list, head) {
+		if (crtc == test_crtc)
+			continue;
+		test_amdgpu_crtc = to_amdgpu_crtc(test_crtc);
+		if (test_amdgpu_crtc->encoder &&
+		    ENCODER_MODE_IS_DP(amdgpu_atombios_encoder_get_encoder_mode(test_amdgpu_crtc->encoder))) {
+			/* for DP use the same PLL for all */
+			if (test_amdgpu_crtc->pll_id != ATOM_PPLL_INVALID)
+				return test_amdgpu_crtc->pll_id;
+		}
+	}
+	return ATOM_PPLL_INVALID;
+}
+
+/**
+ * amdgpu_pll_get_shared_nondp_ppll - return the PPLL used by another non-DP crtc
+ *
+ * @crtc: drm crtc
+ * @encoder: drm encoder
+ *
+ * Returns the PPLL (Pixel PLL) used by another non-DP crtc/encoder which can
+ * be shared (i.e., same clock).
+ */
+int amdgpu_pll_get_shared_nondp_ppll(struct drm_crtc *crtc)
+{
+	struct amdgpu_crtc *amdgpu_crtc = to_amdgpu_crtc(crtc);
+	struct drm_device *dev = crtc->dev;
+	struct drm_crtc *test_crtc;
+	struct amdgpu_crtc *test_amdgpu_crtc;
+	u32 adjusted_clock, test_adjusted_clock;
+
+	adjusted_clock = amdgpu_crtc->adjusted_clock;
+
+	if (adjusted_clock == 0)
+		return ATOM_PPLL_INVALID;
+
+	list_for_each_entry(test_crtc, &dev->mode_config.crtc_list, head) {
+		if (crtc == test_crtc)
+			continue;
+		test_amdgpu_crtc = to_amdgpu_crtc(test_crtc);
+		if (test_amdgpu_crtc->encoder &&
+		    !ENCODER_MODE_IS_DP(amdgpu_atombios_encoder_get_encoder_mode(test_amdgpu_crtc->encoder))) {
+			/* check if we are already driving this connector with another crtc */
+			if (test_amdgpu_crtc->connector == amdgpu_crtc->connector) {
+				/* if we are, return that pll */
+				if (test_amdgpu_crtc->pll_id != ATOM_PPLL_INVALID)
+					return test_amdgpu_crtc->pll_id;
+			}
+			/* for non-DP check the clock */
+			test_adjusted_clock = test_amdgpu_crtc->adjusted_clock;
+			if ((crtc->mode.clock == test_crtc->mode.clock) &&
+			    (adjusted_clock == test_adjusted_clock) &&
+			    (amdgpu_crtc->ss_enabled == test_amdgpu_crtc->ss_enabled) &&
+			    (test_amdgpu_crtc->pll_id != ATOM_PPLL_INVALID))
+				return test_amdgpu_crtc->pll_id;
+		}
+	}
+	return ATOM_PPLL_INVALID;
+}